Citrus fruit, such as oranges, for example, is commonly harvested from citrus groves using manual picking and collection techniques. Of course, more automated approaches have also been developed in an attempt to lower harvesting costs. For example, U.S. Pat. Nos. 5,469,695 and 5,513,484; and published international patent applications WO02/089556 and WO02/069693, to Zehavi et al., disclose a harvesting system based upon so-called shake and catch technology. A shaker vehicle carries a shaker head to engage and vibrate a tree trunk to dislodge the fruit therefrom. The shaker head is carried by an extensible boom which can retract and extend the shaker head. In the extended position, the jaws of the shaker head engage the tree trunk and a hydraulically driven vibrator shakes the tree trunk. The shaker head can be retracted by the extensible boom for advancing to the next tree.
A fruit deflector is carried by the shaker vehicle and collects a portion of the fruit. A fruit collector vehicle is positioned along an opposite side of the tree. The fruit collector typically includes one or more fruit conveyors to catch the portion of the fruit falling thereon, as well as to receive fruit from the fruit deflector of the shaker vehicle.
The collected fruit is conveyed by the fruit collector vehicle to be temporarily held in a fruit trailer typically towed behind the fruit collector vehicle. The shaker vehicle and fruit collector vehicle are each advanced to a next tree for harvesting. Once filled, the fruit trailer is movable to a raised height and a door opened to thereby empty its contents into a fruit removal vehicle. The fruit removal vehicle is intermittently brought adjacent the fruit trailer to receive the fruit therefrom and transport the fruit to a collection area.
Of significant interest in the automated harvesting technology are efficiency of fruit collection, speed of collection, and, of course, cost and reliability of the various pieces of harvesting and collection equipment. Efficiency of fruit collection relates not only to the percentage of fruit shaken from the tree and collected, but also to how much fruit may be lost by damage in subsequent handling.
It is also typically important that the fruit collector efficiently collect fruit for discharge into the fruit trailer. A typical fruit collector, such as disclosed in U.S. Pat. No. 5,513,484 to Zehavi et al., includes an inclined collection conveyor and an intermediate conveyor adjacent the upper end of the inclined conveyor for conveying fruit to the rear of the vehicle. At this location, another conventional inclined conveyor extends outwardly from the back end of the vehicle. The back conveyor has a lower end and an upper end and an exterior conveyor surface extending therebetween. The collection efficiency of such an arrangement may be relatively good. Unfortunately, this arrangement of conveyors results in a relatively long apparatus that may be difficult to maneuver in the tight confines of a typical citrus grove, for example. It is also typically a challenge to process a large quantity of fruit and while preventing the accumulation of debris which could reduce harvesting efficiency.
The fruit trailer is also desirably relatively large yet readily operable to discharge fruit into vehicle which is periodically brought up to the trailer. Damage to the fruit during this operation is also desirably avoided. U.S. Pat. No. 5,513,484 discloses a fruit trailer which includes a container portion which is vertically lifted for periodically discharging the fruit. This container lifting arrangement may be relatively complicated and some fruit may be subject to damage during the discharge.